1. Field of the Invention
The present invention relates to a tire vulcanizer in which a green tire is mounted and shaped in a shaping unit outside a vulcanizer body and then the green tire is vulcanized in a state that the shaping unit is moved and set in the vulcanizer body, and particularly it relates to a tire mounting technique for mounting a green tire in the shaping unit outside the vulcanizer body.
2. Description of the Related Art
According to prior art tire vulcanization methods such as one disclosed in Japanese Laid-open Patent Application Publication No. 2002-120228, for shaping a green tire, the green tire is set in a center mechanism of a vulcanizer and a bladder of the center mechanism is inflated with a pressurized fluid to thereby make the outer circumference of a bladder in tight contact with the inner circumference of the green tire.
Next, the green tire is held in a container of the vulcanizer, and then the inner circumference thereof is pressed into the bladder supplied with a high-temperature and pressure fluid, thereby vulcanizing the green tire by heat from the bladder and the container.
However, such a prior art tire vulcanization method has a problem that the green tire is set in the center mechanism of the vulcanizer for shaping so that pre-vulcanization processing takes a long time, causing a reduction in work efficiency.
In view of solving the above problem, in prior art there has been proposed a tire vulcanizer disclosed in Japanese Laid-open Patent Application Publication No. 2003-537312 which shapes a green tire with a shaping unit outside a vulcanizer body and vulcanizes the shaped green tire with the shaping unit kept set in the vulcanizer body.
This prior art tire vulcanizer includes a shaping unit for off-line setup, that is, mounting a green tire outside the vulcanizer body and shaping the green tire.
Thus, the use of the shaping unit has an advantage of improved work efficiency since just setting in the vulcanizer body the green tire shaped thereoutside enables immediate start of vulcanization.
In order to manufacture tires with high performance, however, it is essential to not only accurately mold the green tire but also to set the green tire in a container of the vulcanizer body accurately without positional and directional displacement.
Therefore, for shaping the green tire in the shaping unit, it is necessary to mount the green tire in the shaping unit accurately and shape it accurately.
In this point, the shaping unit of the prior art tire vulcanizer is structured exactly the same as the center mechanism of the tire vulcanizer disclosed in Japanese Laid-open Patent Application Publication No. 2002-120228 above and it lacks a beadlock for the green tire.
Having such a structure as that of the center mechanism, a problem arises that the structure thereof is complicated since it needs to have a center post, a cylinder and the like.
Furthermore, due to the lack of beadlock for the green tire, there is a problem that the green tire is likely to be positionally or posturally displaced when mounted in the shaping unit, and accordingly it cannot be mounted and shaped in the shaping unit accurately.
In view of solving the above-identified problems, the present invention aims to provide a tire vulcanizer with a vulcanizer body and a shaping unit in which the green tire is accurately mounted and accurately shaped in the shaping unit so that the green tire can be set accurately in a lower container of the vulcanizer body when the shaping unit is placed in a container thereof.